lower bound = 39

C(22,4,2) = 39

Method of Construction: mill, jcta 15 (1973) 138-166

Lower Bound: Schonheim

  1  2  3  4
  1  2  5  6
  1  2  7  8
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  1 11 12 13
  1 14 15 16
  1 17 18 19
  1 20 21 22
  2 11 14 17
  2 12 15 20
  2 13 18 21
  2 16 19 22
  3  5 11 16
  3  6 13 15
  3  7 12 18
  3  8 14 22
  3  9 17 20
  3 10 19 21
  4  5 18 20
  4  6 17 22
  4  7 11 19
  4  8 15 21
  4  9 12 14
  4 10 13 16
  5  7 14 21
  5  8 13 17
  5  9 15 19
  5 10 12 22
  6  7 16 20
  6  8 12 19
  6  9 11 21
  6 10 14 18
  7  9 13 22
  7 10 15 17
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  8 10 11 20
 11 15 18 22
 12 16 17 21
 13 14 19 20